Why aren't RP black drums compatible?

[mixedfeelings]

Ah, so does that mean that color drums do not print at 600 dpi? Only the HD black is capable of that?

How is the HD ink itself different? Is it thicker?

[ddude]

I would think the HD ink is thinner, allowing it to flow into the smaller pinholes burnt into the master.
I do not know if the 37xx will burn a different DPI master when it senses that a color drum is installed- That is a question best left to the experts??? IF- it does not burn a different DPI master, then we can deduce only two things:
1) that Riso color ink is capable of flowing through a fine,thinly burned 600dpi master, or-
2) that the whole HD concept put out by Riso is hooey.

[jermyth]

For whatever reason Riso does not make HD color ink only HD Black ink. Do color drums print better with a HD master on them? Most say yes. Personally...somewhat, it depends on the image.